Android Date Picker

Android has been created a specific dialog to select a date from but, sometimes we can’t use that or we have to implement a view which is more simple or can become more custom.
In one of my project I decided to design and develop my own Date Picker cause I didn’t find any sutible date picker library. Here is my date picker that consist of a Java file which named MyDatePicker.java and a XML file which named view_date_picker.xml that must be located in layout directory. I would be happy if anyone help me to improve this class.

Android Date Picker

MyDatePicker.java

public class MyDatePicker extends FrameLayout {

    private TextView tvYear;
    private TextView tvMonth;
    private TextView tvDay;
    private Context context;

    private ArrayList<String> year = new ArrayList<String>();
    private ArrayList<String> month = new ArrayList<String>();
    private ArrayList<String> day = new ArrayList<String>();

    private int yearFrom = 2000;
    private int yearUntil = 2019;

    public MyDatePicker(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        this.context = context;

        initView();
    }

    public void initYear(int yearFrom, int yearUntil) {
        this.yearFrom = yearFrom;
        this.yearUntil = yearUntil;
        fillYear();
    }


    public void initView() {
        final View view = inflate(getContext(), R.layout.view_date_picker, null);

        tvYear = view.findViewById(R.id.tvYear);
        tvMonth = view.findViewById(R.id.tvMonth);
        tvDay = view.findViewById(R.id.tvDay);

        fillDay();
        fillMonth();
        fillYear();

        tvMonth.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                dialog(view, tvMonth, month);
            }
        });

        tvDay.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                dialog(view, tvDay, day);
            }
        });
        tvYear.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                dialog(view, tvYear, year);
            }
        });

        addView(view);
    }

    public void setYear(int year) {
        tvYear.setText(year + "");
    }

    public void setMonth(String month) {
        tvMonth.setText(month);
    }

    public void setMonth(int month) {
        tvMonth.setText(convertNumToMonth(month));
    }

    public void setDay(int day) {
        tvDay.setText(day + "");
    }

    public ArrayList<String> getMonthList() {
        return month;
    }


    private void dialog(final View view, final TextView tv, final ArrayList<String> array) {

        //convert arraylist to string array:
        String[] convertedArray = new String[array.size()];
        convertedArray = array.toArray(convertedArray);

        AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
        builder.setItems(convertedArray, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                tv.setText(array.get(which));
            }
        });
        AlertDialog dialog = builder.create();
        dialog.show();
    }

    public int getDay() {
        if (tvDay.getText().toString().equals("Day")) return 0;
        else return Integer.parseInt(tvDay.getText().toString());
    }

    public int getMonthInNum() {
        if (tvMonth.getText().toString().equals("Month")) return 0;
        else return convertMonthToNum(tvMonth.getText().toString());
    }

    public String getMonthInString() {
        if (tvMonth.getText().toString().equals("Month")) return null;
        else return tvMonth.getText().toString();
    }

    public int getYear() {
        if (tvYear.getText().toString().equals("Year")) return 0;
        else return Integer.valueOf(tvYear.getText().toString());
    }

    public boolean isDatePickerValid() {
        if (tvYear.getText().toString().equals("Year") || tvMonth.getText().toString().equals("Month") || tvDay.getText().toString().equals("Day") || tvYear.getText().toString().length() < 4 || Integer.parseInt(tvYear.getText().toString()) < yearFrom || Integer.parseInt(tvYear.getText().toString()) > yearUntil)
            return false;
        else return true;
    }


    private void fillDay() {
        day.clear();
        day.add("Day");
        for (int i = 1; i < 32; i++) {
            day.add(i++ + "");
        }
    }

    private void fillMonth() {
        month.clear();
        month.add("Month");
        month.add("January");
        month.add("February");
        month.add("March");
        month.add("April");
        month.add("May");
        month.add("June");
        month.add("July");
        month.add("August");
        month.add("September");
        month.add("October");
        month.add("November");
        month.add("December");
    }

    private void fillYear() {
        year.clear();
        year.add("Year");
        for (int i = yearFrom; i < yearUntil; i++) {
            year.add(i++ + "");
        }
    }

    private static int convertMonthToNum(String s) {

        switch (s) {
            case "January":
            case "january":
            case "Jan":
            case "jan":
                return 1;
            case "February":
            case "february":
            case "Feb":
            case "feb":
                return 2;
            case "March":
            case "march":
            case "Mar":
            case "mar":
                return 3;
            case "April":
            case "april":
            case "Apr":
            case "apr":
                return 4;
            case "May":
            case "may":
                return 5;
            case "June":
            case "june":
            case "Jun":
            case "jun":
                return 6;
            case "July":
            case "july":
            case "Jul":
            case "jul":
                return 7;
            case "August":
            case "august":
            case "Aug":
            case "aug":
                return 8;
            case "September":
            case "september":
            case "Sep":
            case "sep":
                return 9;
            case "October":
            case "october":
            case "Oct":
            case "oct":
                return 10;
            case "November":
            case "november":
            case "Nov":
            case "nov":
                return 11;
            case "December":
            case "december":
            case "Dec":
            case "dec":
                return 12;
        }

        return 0;
    }

    private static String convertNumToMonth(int num) {

        switch (num) {
            case 1:
                return "January";
            case 2:
                return "February";
            case 3:
                return "March";
            case 4:
                return "April";
            case 5:
                return "May";
            case 6:
                return "June";
            case 7:
                return "July";
            case 8:
                return "August";
            case 9:
                return "September";
            case 10:
                return "October";
            case 11:
                return "November";
            case 12:
                return "December";
        }

        return null;
    }

}

view_date_picker.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_margin="5dp"
        android:background="@drawable/btn_white"
        android:elevation="2dp"
        android:gravity="center_vertical"
        android:orientation="horizontal"
        android:padding="2dp">

        <TextView
            android:id="@+id/tvDay"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_marginRight="5dp"
            android:layout_weight="1"
            android:gravity="center"
            android:text="Day"
            android:textColor="#424242"
            android:textSize="12dp" />

        <ImageView
            android:layout_width="7dp"
            android:layout_height="7dp"
            android:layout_marginBottom="5dp"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="15dp"
            android:layout_marginTop="5dp"

            android:background="@drawable/ic_dropdown" />


        <LinearLayout
            android:layout_width="1dp"
            android:layout_height="match_parent"
            android:layout_marginLeft="10dp"
            android:background="#e0e0e0"></LinearLayout>

        <TextView
            android:id="@+id/tvMonth"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_marginLeft="4dp"
            android:layout_marginRight="5dp"
            android:layout_weight="1"
            android:gravity="center"
            android:text="Month"
            android:textColor="#424242"
            android:textSize="12dp" />

        <ImageView
            android:layout_width="7dp"
            android:layout_height="7dp"
            android:layout_marginLeft="2dp"
            android:background="@drawable/ic_dropdown" />

        <LinearLayout
            android:layout_width="1dp"
            android:layout_height="match_parent"
            android:layout_marginLeft="10dp"
            android:background="#e0e0e0"></LinearLayout>

        <TextView
            android:id="@+id/tvYear"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_marginRight="5dp"
            android:layout_weight="1"
            android:gravity="center"
            android:text="Year"
            android:textColor="#424242"
            android:textSize="12dp" />

        <ImageView
            android:layout_width="7dp"
            android:layout_height="7dp"
            android:layout_marginBottom="5dp"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="15dp"
            android:layout_marginTop="5dp"

            android:background="@drawable/ic_dropdown" />


    </LinearLayout>

</LinearLayout>

Usage

MyDatePicker myDatePicker;
myDatePicker = findViewById(R.id.datePicker);
myDatePicker.initYear(1995,2019); //Optional (default is 2000 to 2019)
myDatePicker.initView();//Important part!

myDatePicker.setDay(23);
myDatePicker.setMonth(2);
myDatePicker.setYear(2018);


//functions :
myDatePicker.getDay();
myDatePicker.getMonthInNum();
myDatePicker.getMonthInString();
myDatePicker.getYear();

myDatePicker.invalidate();